1. Field of the Invention
The invention relates to a wireless input device, especially refers to a keyboard furnished with a plurality of RFID (Radio Frequency Identification) tag units that can be operated without the need of internal electric power.
2. Description of the Prior Art
Conventional input devices such as keyboards for computers, include cabled keyboards and wireless keyboards. The cabled keyboard is connected with the computer via a cable and thus can acquire electric power from the computer for operations. However, for those conventional wireless keyboards, batteries are required to be built inside the wireless keyboards in order to provide electric powers for operations. Almost all users of the wireless keyboards have been experienced the same inconvenience that, when the power of the battery is getting low, lost or error signals will happen frequently when operating the wireless keyboards. Not only the need to change batteries frequently is a significant drawback of the conventional wireless keyboards, but also the battery itself will cause the size and weight of wireless keyboard bulky. Situation might become even worse, when the user cannot find any new battery to replace the old one, when he/she found that his/her wireless keyboard is out of power.